There is a much easier more effective way that removes all of the above hassle. You would firstly need to Get a trickle charge such as NOCO or CTek. Then you will also need optional cigarette lighter leader. Simply plug it into the in car cigar lighter and leave for around 10 minutes. Bobs your uncle power will start to restore to your battery and sufficient power will be available to pop the Frunk. It’s the way I’ve been doing it on my 911 for years and works a treat!
Yes, dependant on which model you have as they are all slightly different you can even do it it on the most recent 992. You will need to use the emergency key blade but it’s not complicated.